fun main() {
    val list = listOf("jason", "jack", "jacky")
    for (s in list) {
        println(s)
    }
    list.forEach{
        println(it)
    }

    list.forEachIndexed{ index, item ->
        println("$index, $item")
    }

    //_过滤不想赋值的元素
    val (origin, _, proxy) = list

}